Hiệu ứng sẽ tính xem tháng hiện hành có bao nhiêu ngày thứ Tư.
HTML
<SCRIPT LANGUAGE="JavaScript">
// Michael Mann , http://www.manninc.com
var now = new Date();
var month = now.getMonth();
var date = now.getDate();
var day = now.getDay();
var year = now.getYear();
m = new Array("January","February","March","April","May","June","July",
"August","September","October","November","Decemeber");
d = new Array("Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday");
if (year < 2000) year = year + 1900;
//End of Month Calculations
var monarr = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
// check for leap year
if (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) monarr[1] = "29";
//Finds the First Day for the Current Month
while (date != 1){
date = date - 1;
day = day - 1;
if (day < 0) day = day + 7;
}
//Counts Number of Wednesdays in the Current Month
weekday = 0;
while (date != monarr[month]){
date = date + 1;
day = day + 1;
if (day > 6)
day = 7 - day;
if (d[day] == "Wednesday")
weekday = weekday + 1;
}
//Fix For Months beginning on a Wednesday
if (d[day] == "Wednesday") weekday = weekday + 1;
document.write (m[month] + " contains " + weekday + " " + d[3] + "s");
</script>